Automatic switch



0. E. RASMUSSEN.

AUTOMATIC SWITCH.

APPLICATION FILED 054:.1. 19:5.

1 ,324:,84:7. Patented Dec. 16, 1919.

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OSVALD E. RASMUSSEN, WEST HOBOKEN, NEW JERSEY, ASSIGNOB TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

AUTOMATIC SWITCH.

To all whom it may concern:

Be it known that I, OSVALD E. Rasmussen, a subject of the King of Denmark, residing at West Hoboken, in the county of Hudson and State of New Jersey, have invented certain new and useful Improvements in Autoniatic Switches, of which the following is a full, clear, concise, and exact description.

This invention relates to automatic switches for use in telephone exchan e systems, and more particularly to switc es of the multiple brush type.

In switches of this type it is customary to first render operative one of a certain set of brushes, after which such selected brush is moved in group steps over the section served by it. At the completion of the group ste s, short steps are taken to select a particu ar terminal set in the selected It is the object of this invention to provide a switch of these general characteristics in which simplicity of structure and operation is attained.

A feature of the resent invention is the utilization of a singlia magnet to control the brush selection, group selection, and individual terminal selection. This magnet controls a double escapement, one of whose pallets may be rendered inoperative at certain times.

The general construction of the contact bank. brush sets and tri ping mechanism, may be similar to that disclosed in Patent No. 1,123,696, issued January 5, 1915, to E. B. Craft and J. N. Reynolds.

It is thought that the invention will best be understood from the following detailed description, reference being had to the accompanying drawing.

In the drawing, Figure l is a side elevation of the switch showin its general structure; Fig. 2 is a detail view of the controlling inagnet and double escapement operated bv it. showing also the arrangement of the slots in the driving ribbon: Fig. 3 shows a circuit arrangement suitable for operation with the switch of the present invention.

The switch. as described, is arranged for Specification of Letters Patent.

Patented Dec. 16, 1919;

Application flied December 1, 1916. Serial No. 134,340.

fingers 6 and operated by a trip magnet 7..

Tri rod 5 and magnet 7 are common to all the rushes of the switch, the brush set to be tripped being determined by the extent of primary motion of shaft 1, as described in the above mentioned atent.

To the lower end o shaft 1 is attached a driving ribbon 8,having two rows of slots punched therein.

An escapement consisting of pallets 9, 10 and 11 is arranged to be operated by a spacing member 12 controlled by the armature 13 of a magnet 14 by means of a bell-crank lever 15.

The lower portion of trip rod 5 carries a U-shaped member 16, so arranged that when the trip rod is rotated. an extension 17 will be thrown into the path of travel of a stud 18 carried by pallet 11.

Referring now to Fig. 2, it willbe seen that two series of slots are punched in'the driving ribbon 8. the slots 19 being arranged to allow the shaft 1 to be advanced in short steps under the control of the escapement members 9 and 11, while the long slots are arranged to allow-the shaft 1 to be advanced in long steps under the control of escapement members 9 and 10. The topmost long slot is equivalent to five of the short slots, the remainder of the long slots being each equivalent to ten of the small slots.

The general operation of the structure is as follows: Upon energization of magnet 14, pallet'9 is withdrawn from the upper slot 19 and pallet 11 will engage the second slot when the ribbon 8 is carried upward by the action of spiral spring 2. Upon deiinergization of magnet 14. the ribbon 8 will be aduse as a selector, but may he obviously ag- -nsuncod a trifle to allow pallet 9 to engage the rangedto perform any of the functions'u'sual second slot 19. SH'U'B the pallet 11 is some to a switc i of this type.

what shorter than pallet 9. A spring 20 (indicated in Fig. 1) tends to draw pallets 9 and 11 together, and also in a similar manner a spring (not shown tends to draw pallets 9 and 10 together. this way the driving ribbon may be advanced in short steps to position a brush set for tr pping. Carried by each brush set is a tripping lug 21, it being understood that these lugs 21 are spaced at constantly increasing distances from their respective trip fingels. 6, as described in the previously mentioned patent. The trip rod 5 is now rotated to render 0 erative 11 positioned set of brushes, and in rotating, extension 17 is thrown in the patn of stud 18.'

When magnet 14 is energized in response to the first of the group selecting impulses, pallet 10 will be thrown forward and en age the bottom of the topmost long slot. pon deenergization of magnet 14, the ribbon will be advanced upwardly a 'suflicient amount to allow pallet 9 to engage slot 19', thereby holding the brush set in position below the first group of terminals. It IS to be noted that the engagement of stud 18 wlth extension 17 prevents the operation of pallet 11, which would otherwise interfere and revent a. long step from being taken. he brush shaft Lisadvanced u ward in long steps under the control of t e escapement as though the escapement were composed only of pallets 9 and 10.

At the conclusion of the group impulses, the trip rod 5 is restored to normal position and the brush shaft 1 is advanced in short steps under the control of the escapement consisting of pallets 9 and 11 as before, since the release of trip rod 5 has allowed pallet 11 to again become operative. I

Referring now to Fig. 3, the o eration of circuits sultable for use with his switch when operating as a selector is as follows: When the subscriber at substation 31'removes his receiver, his line is extended to the selector whose circuits are .shown, in the well-known manner, by the operation of either a line switch or a line finder. A circuit is thereupon com leted for stepping rela 32 from groun ed battery, left-hand winding of relay 32, side-switch wiper 33 in its first position, throu h the brushes .of the preceding switch and t ie loop of the calling subscriber, side-switch wiper 34 in its first osition. and the right-hand winding of reay 32 to ground. Relay 3-2 is energized and completes a circuit for slow-release relay 35 fiom grounded battery, winding of relay 35, to ground at the armature and front contact of relay 32.

A series of impulses is now sent to select a brush. Upon the first interruption of the line circuit, relay 32 is (le'cncrgized and a circuit for slow-release escape magnet 36 is completed from grounded battery, winding of magnet 36, armature and front contact of relay 35, armature and back contact of relay 32, to ground. The escape magnet is ener ized but does not release the side switch. At the same time a circuit is completed for step ing magnet 14 from grounded battery, win ing of magnet 14, side-switch wiper 39 and its first contact, armature and front contact of relay 35, and armature and back contact of relay 32 to ground. Upon each deenergization of relay 32, ste ping magnet 14 is energized and the brush shaft is advanced in short steps underthe control of the escapement composed of pallets 9 and 11. At the conclusion of the first series of impulses, rela 32 remains energized for a comparatively lon time, whereupon escape magnet 36 is eenergized and releases the side switch into position 2.

In position 2 of the side-switch wipers, trip magnet 7 is energized over a circuit from grounded battery, winding of magnet 7, side-switch wiper 37 in its second position to ground. The operation of magnet 7 trips a positioned set of brushes and throws extension 17 into the path of travel of stud 18 to render allet 11 inoperative.

Stepping re ay 32 is 'now operated by a second train of impulses over side-switch wipers 33 and 34 in their second positions, to control the oup selecting operation of the switch. Re ays 35 and 36 are energized as before, as is also magnet 14, but at this time magnet 14 controls an escapement composed o pallets 9 and 10 previously described, and the brush set is advanced in long steps. At the conclusion of this sec ond series of impulses, escape magnet 36 is denergized as before and moves the sideswitch wipers from position 2 into position 3. Trip magnet 7 is thereupon denerg'ized and returned to its normal position, rendering pallet 11 againoperative.

In the third position of the side-switch, magnet l-l interrupts its own circuit at its armature and back contact, this circuit being from grounded battery, winding of magnet 14, side-switch 39 and its third contact, armature and back contact of magnet 14 to ground. Assuming that an i le condition of trunks is represented by t e presence of ground on their test terminals, and a busy condition of trunks by t-he'absence of such ground, escape magnet 36 will not be energized until an idle trunk is found, the side switch being so constructed that the magnet 36 will release it from its third to its fourth position upon the energization of the escape magnet. The selected brush set will now be advanced over the terminal sets in the desired group until an idle trunk is found, at which time the presence of ground on the test terminal of such trunk will allow escape magnet 36 to energize and release the side switch into its fourth position over a circuit from grounded battery, winding of ma et 36, side-switch wiper 38 and its thi contact, test brush of the selected set to ground at the terminal of the idle trunk. In the fourth position of the side switch, the operating circuit for stepping'magnet 14 is opened and the subscrlbers" line conductors are extended to a desired trunk .overwhich further connection may be established in any desired manner.

At the conclusion of conversation, und will be reapplied to the test terminal of the selected trunk bythe release of the succeeding SWitCh,-8,t which time a circuit will be completed for down-drive power magnet 40 from grounded battery,- windingof magnet 40, off-normal contact 41, side-switch wiper 38 in its fourth position, to ground. Magnet 40, in ener 'zing, completes a looking circuit for itse f through its armatureand front contact, and at the same time forces the driving ribbon 8 into engagement with the constantly rotating roller 42 to cause the restoration of the switch. When the switch arrives in .its normal position, contact 41 will be opened to break the looking circuit of magnet 40.

The side switch is restored in the usual manner by the return of the brush set, and on leaving position 4 maintains ground for the release of the preceding switch 'over a circuit from ground, armature and lback contacts of relays 32 and 35,side-switch wiper 43 in either first, second or third position, to the test conductor of such precedin switch.

iat is claimed is:

1. In an automatic switch, a movable shaft, movable contacts carried thereby, a plurality of stationary terminal sets arranged for engagement with said movable contacts, means for causing a primary movement of said shaft, means for causing a secondary longitudinal movement of. said shaft, means for causing a tertiary movement of said shaft, and a sin is magnet to mechanically; control all of said movements.

2. In an automatic switch, a movable shaft, movable contacts carried thereby, a plurality of stationary terminal sets, a contact bank containing said terminal sets and arranged to be served by said movable contacts, said terminal sets being arranged in sections and groups, means to select a desired section, means to select a desired group,- means ,to select a desired terminal in said selected group, and a single magnet to mechanically control all of said selecting means.

3. In an automatic switch, a movable shaft, a plurality of multiply-connected brush sets carried thereby, a contact bank divided into sections and groups, there being one of said brush sets er section, said brush sets being normally moperative with respect to the section served by them, means for rendering a desired brush set operative, means for advancing said operative brush set in long steps, means for advancing said operative brush set in. short steps, and a single magnet to control the means for-rendermg a desired brush setoperative and advancing said shaft. 1

t. In an automatic switch, a movable shaft, a plurality of multiply-connected brush sets-carried. thereby, a plurality of terminal sets, a panel contact bank containin said terminal sets, said bank being divi ed into a lurality of sections, there be ing one of said brush sets per section, said brush sets being normally inoperative with respect to the section served by them, means for advancing said movable shaft into a position where a desired one of said brush sets may be made active, means for rendering active said positioned brush set, means for advancing said vactive brush set in long steps, means for advancing said active brush set in short steps, and a single magnet to control the movement of the shaft during the positioning for brush selection and during said long and short steps.

5. In an automatic switch, a movable shaft, movable contacts carried thereby, a plurality of stationaryterminal-sets arranged for engagement by said movable contacts, a magnet, a compound escapement controlled thereby, and means including said magnet and escapement for causing primary, secondary and tertiary movements of said shafts.

6. In a selective switch, a movable shaft, movable contacts carried thereby, a plurality of stationary terminal sets arranged for engagement by said movable contacts, a magnet, a compound escapement controlled thereby, and means including said magnet and escapement to control three selective movements of said shaft.

7. In a selective switch, a movable shaft, movable contacts carried thereby, a plurality of stationary terminal sets arranged for engagement by said movable contacts, a magnet, a compound escapement controlled thereby, said escapement consisting of a plurality of pallets, and means including said magnet and escapement to control three selective movements of said switch, certain of said pallets being inoperative during certain of said selective movements.

8. In an automatic switch, a movable contact carrying shaft, a plurality of sets of stationary contacts arranged for engagement with the contacts on said shaft, means for causing a primary movement of said shaft. means for causing a secondary longitudinal movement of said shaft, means for causing a tertiary movement of said shaft.

and a single means to control all of said movements.

9. In an automatic switch, a movable contact carrying shaft, a plurality of sets of stations. contacts arranged for engagement with t e contacts on said shaft, means for causing a primary movement of said shaft, means for causing a. secondary movement of said shaft, means for eausing a tertiary movement of said shaft, all of said 10 movements bein T longitudinal, and a single means to eontro all of said movements.

In witness whereof I hereunto subscribe my name this 28th day of November, A. D.

GSVALD E. 'RASMUSSEN. 

